The invention relates to a plug-in tongue for a seat belt comprising an inserting portion adapted to be inserted into a belt buckle and a deflecting portion for a belt webbing, wherein the deflecting portion includes a webbing passage as well as a clamping element for the webbing and wherein the clamping element is displaceable between a home position in which the webbing is freely movable and a looking position in which the clamping element is displaced against a well of the webbing passage so that the webbing is clamped between the clamping element and the wall of the webbing passage.
In three-point belts plug-in tongues form a deflecting point between a first portion of the seat belt which in the case of restraint retains the pelvis of the vehicle occupant and a second portion which protects the thorax of the vehicle occupant against forward displacement. The plug-in tongue is threaded with the deflecting portion onto the webbing of the seat belt so that the plug-in tongue can be freely displaced along the webbing, in this way the length of the two portions of the seat belt can be adapted to the vehicle occupant during the fastening operation. In addition, by shifting the webbing by the plug-in tongue the webbing can be aligned so that it is evenly adjacent to the vehicle occupant.
In the case of restraint, the thorax may happen to move forward when the seat belt is locked. Since the webbing is movably guided in the plug-in tongue, the webbing can be displaced so that the portion adjacent to the thorax is lengthened and the portion adjacent to the pelvis is shortened causing the seat belt to pinch in the pelvis region. In order to prevent this, plug-in tongues include clamping elements which can be displaced during locking of the seat belt between a home position in which the webbing is freely movable and a locking position in which the clamping element clamps the webbing to the plug-in tongue so that no webbing displacement is possible between the first and second portions of the seat belt. In this way, the pelvis region is protected from pinching of the seat belt and the thorax is protected from excessive forward displacement.
In the plug-in tongues known, for example, from DE 10 2004 023 394 A1 the webbing passage in which the clamping element is moved into the locking position extends transversely to the longitudinal direction of the plug-in tongue. In the case of restraint, the webbing is forced against the clamping element by the tensile force acting on the webbing. When the webbing is displaced vis-à-vis the plug-in tongue, for example by increased tension on the thorax section, the clamping element is drawn by the webbing into the webbing passage due to the increased friction between the clamping element end the webbing, until the clamping element locks the webbing. The clamping element thus is moved only when the webbing moves in the plug-in tongue.